1. Field of the Invention
This invention relates to shock absorbers for cycles. More particularly, the invention is concerned with shock absorbers for bicycles and motor-cycles for use on rough and uneven roads.
2. Description of the Prior Art
In their normal use, two-wheeled vehicles of the cycle type are conventionally made with rigid forks because usually they are not able to deaden stress forces imparted to the frame, due to road-bed unevenness, and therefore, rigid forks are used only on level and substantially even roads.
There has now arisen on the market a new type of bicycle and motor-cycle which are primarily used in a sales directed to the realization of bicycles and motor-bicycles for sport activity and are usable on mixed roads, such as an uneven hilly ground. These types of bicycles and motor-bicycles have brought into use devices known as telescopic re-entry front forks which are equipped with shock absorbers for impact stress absorption. One form of prior art, which uses spring mechanical members to obviate a kick back effect that such springs cause on the frame, is the use of hydraulic shock absorbers which provide for a soft damping. These type of shock absorbers provide for a non-variable damping effect, are adjustable from the ground by setting of a throttle valve. Consequently, with these types of shock absorbers, it is not possible to adjust the damping effect as occasion may require. Furthermore, these shock absorbers which use an oil circulation system with a sole pipe and which act with different types of valves are subject to a quick deterioration because a jamming action may arise which is caused by flow residues, or a possible shortcoming between the different parts and, therefore, they are hindered in their operation.